Adding-machine



(No Model.)

T. A. TRENT, Jr. ADDING MACHINE.

No. 508,450. Patented Nov. 14, 1893.

m: mmomu. umuaRAF-Nma COMPANY. WASHINGTON. o, c,

UNITED STATES PATENT OFFICE.

THOMAS A. TRENT, J R,

or DES MOINES, IOWA.

ADDING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 508,450, dated November14, 1893.

Application filed November 28, 1892- Serial No. 453,429. (No model.)

To alt whom it may concern.-

Be 1t known that I, THOMAS A. TRENT, J r., a citizen of the UnitedStates of America, re-

, siding at Des Moines, in the county of Polk and State of Iowa, haveinvented an Improved Adding-Machine, of which the following is aspecification. I

My object is to provide a cheap, simple and durable adding machine whichshall be capable of easy and accurate operation and which shalloccupy aminimum of space; and my invention consists in the construction,arrangement and combination of the various mechanical elementsconstituting the device as hereinafter set forth, pointed out in myclaims and illustrated in the accompanying drawings, in which- Figure 1is a vertical longitudinal sectional View of complete machine. Fig. 2 isan enlarged detail side view; of a part of the operative mechanism.Fig.is a transverse sectional view of the same. Fig. 4 is a top or planview of the com plete machine with parts of the casing removed to showthe operative mechanism. Fig. 5 is an enlarged detail perspective viewof one of the operating levers and a portion of one of the rackspivotally connected therewith and a spring to engage the rack and Fig. 6is an enlarged detail view of one of the operative levers and the lowerend of one of the keys connected therewith.

Referring to the accompanying drawings A designates the inclosing casingof the operative mechanism. -A designates levers pivoted in the forwardportion of the casing and extending rearwardly longitudinally thereof.Connected with their rear end portions are the coil springs A tonormally hold them to the upward limit of their stroke. Extendedhorizontally through the rear portion of the casing is an axle B andloosely mounted upon that axle are a-plurality of registering disks Bhaving broad edges upon which at regular distances apart are placednumerals ranging from 0 to 9, and attached to the hub of each of thesedisks is a pinion B which has a toothB projecting outwardly from itsside for purposes hereinafter set forth.

G designates brackets secured to the casings A and adapted to support anaxle (J in proximity to the pinions B There is one of these axles O toeach of the registering disks, and two brackets are required for eachaxle as clearly shown in the drawings. Fixed to these axles are thesegmental pinions O and the ratchet wheel 0 and loosely mounted on thesame axle between the segmental pinion C and the' ratchet Wheel is apinion C which has a spring actuated pawl G attached thereto andnormally in engagement with the ratchet wheel 0 with the pinion B sothat when the segmental pinion G is moved the motion will be transmittedto the pinion 0 through the instrumentality of the pawl and ratchet whenro-Z tated in the proper direction and this will advance the registeringdisk by reason of the pinion C being in engagement with the pinion B 0is a spring pawl normallyin engagement with the pinion C to prevent itsaccidental rotation.

The inner portion of each of the registering disks (with the exceptionof the first one on the right hand side) is provided with teethD on theinner portion of its rim. D designates brackets secured to the casing A,and D and D are two pinions journaled to each bracket and in mesh witheach other. The one D? is normally in mesh with the teeth on theregistering wheels B and the other one D is.

in position to be engaged by the tooth B each time the pinion B isrotated one complete revolution. These parts are so arranged relative toeach other that each time the pinion B makes a complete revolution thetooth B by engaging the train of gear wheels will move the nextregistering wheel to the left of the pinion B just one-tenth of arevolution.

Motion is imparted to this mechanism as follows:

F designates racks one of which is pivotally connected with each of thelevers A and normally held in engagement with the segmental pinions C bymeans of thesprings F which are fixed to thelevers A and their free endsimpinge the racks. It will now be obvious that the distance theregistering disks will be rotated is regulated by the length of strokeimparted to the rack F.

H designates rows of keys in the casing or frame arranged longitudinallyabove each of the levers A and having ten keys to each- This pinion O?is in'engagement row with dig-its marked upon each key rang ing from 1-at the top of the row to O at the lower end thereof.

J designates the key stems extending downwardly through the casing andbifurcated at their lower ends to be placed astride the levers A J arecoil springs encircling the stems J and impinging the casing and thekeys to normally hold them elevated. These keys are so arranged thateach will have a sufficient amount of vertical movement, and by reasonof the differenccsin distance from the pivotal point of the leveradepression of the keys nearest to the pivotal point of the lever andbearing numerals of greater value will move the free end of the lever agreater distance than a depression of the keys farther from the pivotalpoint bearing the numerals of smaller denomination. The relativedistances which these various keys will move the lever A is graduated asfollows. A depression of the first key at the head of the column willmove the lever a suiiicient distance to rotate the registering wheel thedistance between two of the numerals marked thereon. A depression of thekey number 0 will move the registering disk one complete revolution.

K designates an elongated opening formed in the casing immediately abovethe registering disks and of such a width as to reveal but one of thedigits upon each disk.

In the machine shown there are five rows of keys the first from theright representing units, the second tens, the third hundreds, and soon, so that numbers in the tens of thousands maybe registered. It willbe readily seen that the numbers of rows may be increased or diminishedwithout departing from the spirit of my invention.

The practical operation of the machine is as follows':--Assuming that acolumn of fign'r'es were to be added, the keys are depressed whichcorrespond with the various digits of said number each digit in thecolumn which corresponds with its denomination, and each time thatnumbers in any column whose sum total amounts to ten or more aredepressed the next registering disk to the left is moved the distancebetween two of the numbers on the periphery of the disk by means of thetooth B engaging the train of gear wheels in mesh with the teeth on theinner portion of the rim of the registering disk. For example assumingthat the numbers 175 and 684 are to be added-the following keys aredepressed in the order stated: key No. 1 in the third or hundredscolumn; key No. 7 in the second column or tens, and key No. 5 in thefirst or units column. This will rotate the third disk sufficiently tobring the 1 on the periphery thereof into coincidence with the openingHinthe casing. The second disk will show 7, and the first 5. The key No.6 in the third or hundreds column is then depressed which itwill beobvious will bring the numeral 7 onthe third disk i nto coincidence withthe opening I-I. Key No.8 in the second column is then depressed and thesecond disk is rotated sufficiently to perform one complete revolutionand cause the tooth B connected with the second disk to engage the thirddisk and cause it to rotate one-tenth of a revolution and bring thenumeral 8 of said third disk to appear at the opening II, and thenumeral 5 on the second or tens disk to appear at said opening, and adepression of key No. l in the first or units column will cause thenumeral 9 to appear at the opening H.

Having thus described my invention, what I claim as new, and desiretosecure by Letters Patent of the United States therefor, is

1. In an adding machine, the combination of the following elements, towit: a plurality of disks loosely mounted upon asuitableaxle and havingnumerals marked upon their outer peripheries at regular distances, andteeth formed on their inner peripheries, a pinion 13 connected with thehub of each disk and a tooth B projecting from each of said pinions, twopinions D and D to each disk mounted in a suitable support in mesh witheach other and the outer one in mesh with the internal peripheral teethof the said disk and the inner one in the path of the tooth B of thenext pinion B to the right, arranged and combined substantially as andfor the purposes stated.

2. In an adding machine the combination of the following elements, towit: a suitable casing, an axle extended transversely there through, aplurality of disks loosely mounted thereupon and numbers upon theperipheries of the disks, a pinion 13 having a tooth B connected witheach of the said disks as set forth, axles mounted in suitable supportsin alignment with each of the pinions 13", a pinion loosely mounted oneach of said axles in mesh with the pinions B a ratchet wheeltixed toeach axle at the side of said pinions, a spring actuated pawl attachedto the pinionto engage the ratchet wheel, asegmental pinion attached toeach axle, a rack in mesh with each pinion, a lever pivotally connectedwith each rack, a spring to hold the rack in close engagement with thepinion, a rod running through the casing to which the said levers arepivoted, and a spring to normally hold the lovers elevated, springactuated keys to operate the levers, and the pinions D and D mounted onsnitablesupportsand in mesh with each other and one of them in mesh withthe teeth on the interior of the rims of the registering disks and theother in position to be en gaged by the tooth B, all arranged andcombined substantially in the manner set forth for the purposes stated.

THOMAS A. TRENT, JR. Witnesses:

J. RALPH ORWIG, THOMAS G. ORWIG.

